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Diffstat (limited to 'getid3/module.graphic.png.php')
| -rw-r--r-- | getid3/module.graphic.png.php | 519 |
1 files changed, 519 insertions, 0 deletions
diff --git a/getid3/module.graphic.png.php b/getid3/module.graphic.png.php new file mode 100644 index 0000000..b5b3d35 --- /dev/null +++ b/getid3/module.graphic.png.php @@ -0,0 +1,519 @@ +<?php +///////////////////////////////////////////////////////////////// +/// getID3() by James Heinrich <info@getid3.org> // +// available at http://getid3.sourceforge.net // +// or http://www.getid3.org // +///////////////////////////////////////////////////////////////// +// See readme.txt for more details // +///////////////////////////////////////////////////////////////// +// // +// module.graphic.png.php // +// module for analyzing PNG Image files // +// dependencies: NONE // +// /// +///////////////////////////////////////////////////////////////// + + +class getid3_png +{ + + function getid3_png(&$fd, &$ThisFileInfo) { + + // shortcut + $ThisFileInfo['png'] = array(); + $thisfile_png = &$ThisFileInfo['png']; + + $ThisFileInfo['fileformat'] = 'png'; + $ThisFileInfo['video']['dataformat'] = 'png'; + $ThisFileInfo['video']['lossless'] = false; + + fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET); + $PNGfiledata = fread($fd, GETID3_FREAD_BUFFER_SIZE); + $offset = 0; + + $PNGidentifier = substr($PNGfiledata, $offset, 8); // $89 $50 $4E $47 $0D $0A $1A $0A + $offset += 8; + + if ($PNGidentifier != "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A") { + $ThisFileInfo['error'][] = 'First 8 bytes of file ('.getid3_lib::PrintHexBytes($PNGidentifier).') did not match expected PNG identifier'; + unset($ThisFileInfo['fileformat']); + return false; + } + + while (((ftell($fd) - (strlen($PNGfiledata) - $offset)) < $ThisFileInfo['filesize'])) { + $chunk['data_length'] = getid3_lib::BigEndian2Int(substr($PNGfiledata, $offset, 4)); + $offset += 4; + while (((strlen($PNGfiledata) - $offset) < ($chunk['data_length'] + 4)) && (ftell($fd) < $ThisFileInfo['filesize'])) { + $PNGfiledata .= fread($fd, GETID3_FREAD_BUFFER_SIZE); + } + $chunk['type_text'] = substr($PNGfiledata, $offset, 4); + $offset += 4; + $chunk['type_raw'] = getid3_lib::BigEndian2Int($chunk['type_text']); + $chunk['data'] = substr($PNGfiledata, $offset, $chunk['data_length']); + $offset += $chunk['data_length']; + $chunk['crc'] = getid3_lib::BigEndian2Int(substr($PNGfiledata, $offset, 4)); + $offset += 4; + + $chunk['flags']['ancilliary'] = (bool) ($chunk['type_raw'] & 0x20000000); + $chunk['flags']['private'] = (bool) ($chunk['type_raw'] & 0x00200000); + $chunk['flags']['reserved'] = (bool) ($chunk['type_raw'] & 0x00002000); + $chunk['flags']['safe_to_copy'] = (bool) ($chunk['type_raw'] & 0x00000020); + + // shortcut + $thisfile_png[$chunk['type_text']] = array(); + $thisfile_png_chunk_type_text = &$thisfile_png[$chunk['type_text']]; + + switch ($chunk['type_text']) { + + case 'IHDR': // Image Header + $thisfile_png_chunk_type_text['header'] = $chunk; + $thisfile_png_chunk_type_text['width'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 4)); + $thisfile_png_chunk_type_text['height'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 4)); + $thisfile_png_chunk_type_text['raw']['bit_depth'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 8, 1)); + $thisfile_png_chunk_type_text['raw']['color_type'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 9, 1)); + $thisfile_png_chunk_type_text['raw']['compression_method'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 10, 1)); + $thisfile_png_chunk_type_text['raw']['filter_method'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 11, 1)); + $thisfile_png_chunk_type_text['raw']['interlace_method'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 12, 1)); + + $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['raw']['compression_method']); + $thisfile_png_chunk_type_text['color_type']['palette'] = (bool) ($thisfile_png_chunk_type_text['raw']['color_type'] & 0x01); + $thisfile_png_chunk_type_text['color_type']['true_color'] = (bool) ($thisfile_png_chunk_type_text['raw']['color_type'] & 0x02); + $thisfile_png_chunk_type_text['color_type']['alpha'] = (bool) ($thisfile_png_chunk_type_text['raw']['color_type'] & 0x04); + + $ThisFileInfo['video']['resolution_x'] = $thisfile_png_chunk_type_text['width']; + $ThisFileInfo['video']['resolution_y'] = $thisfile_png_chunk_type_text['height']; + + $ThisFileInfo['video']['bits_per_sample'] = $this->IHDRcalculateBitsPerSample($thisfile_png_chunk_type_text['raw']['color_type'], $thisfile_png_chunk_type_text['raw']['bit_depth']); + break; + + + case 'PLTE': // Palette + $thisfile_png_chunk_type_text['header'] = $chunk; + $paletteoffset = 0; + for ($i = 0; $i <= 255; $i++) { + //$thisfile_png_chunk_type_text['red'][$i] = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1)); + //$thisfile_png_chunk_type_text['green'][$i] = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1)); + //$thisfile_png_chunk_type_text['blue'][$i] = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1)); + $red = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1)); + $green = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1)); + $blue = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1)); + $thisfile_png_chunk_type_text[$i] = (($red << 16) | ($green << 8) | ($blue)); + } + break; + + + case 'tRNS': // Transparency + $thisfile_png_chunk_type_text['header'] = $chunk; + switch ($thisfile_png['IHDR']['raw']['color_type']) { + case 0: + $thisfile_png_chunk_type_text['transparent_color_gray'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 2)); + break; + + case 2: + $thisfile_png_chunk_type_text['transparent_color_red'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 2)); + $thisfile_png_chunk_type_text['transparent_color_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 2)); + $thisfile_png_chunk_type_text['transparent_color_blue'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 2)); + break; + + case 3: + for ($i = 0; $i < strlen($chunk['data']); $i++) { + $thisfile_png_chunk_type_text['palette_opacity'][$i] = getid3_lib::BigEndian2Int(substr($chunk['data'], $i, 1)); + } + break; + + case 4: + case 6: + $ThisFileInfo['error'][] = 'Invalid color_type in tRNS chunk: '.$thisfile_png['IHDR']['raw']['color_type']; + + default: + $ThisFileInfo['warning'][] = 'Unhandled color_type in tRNS chunk: '.$thisfile_png['IHDR']['raw']['color_type']; + break; + } + break; + + + case 'gAMA': // Image Gamma + $thisfile_png_chunk_type_text['header'] = $chunk; + $thisfile_png_chunk_type_text['gamma'] = getid3_lib::BigEndian2Int($chunk['data']) / 100000; + break; + + + case 'cHRM': // Primary Chromaticities + $thisfile_png_chunk_type_text['header'] = $chunk; + $thisfile_png_chunk_type_text['white_x'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 4)) / 100000; + $thisfile_png_chunk_type_text['white_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 4)) / 100000; + $thisfile_png_chunk_type_text['red_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 8, 4)) / 100000; + $thisfile_png_chunk_type_text['red_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 12, 4)) / 100000; + $thisfile_png_chunk_type_text['green_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 16, 4)) / 100000; + $thisfile_png_chunk_type_text['green_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 20, 4)) / 100000; + $thisfile_png_chunk_type_text['blue_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 24, 4)) / 100000; + $thisfile_png_chunk_type_text['blue_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 28, 4)) / 100000; + break; + + + case 'sRGB': // Standard RGB Color Space + $thisfile_png_chunk_type_text['header'] = $chunk; + $thisfile_png_chunk_type_text['reindering_intent'] = getid3_lib::BigEndian2Int($chunk['data']); + $thisfile_png_chunk_type_text['reindering_intent_text'] = $this->PNGsRGBintentLookup($thisfile_png_chunk_type_text['reindering_intent']); + break; + + + case 'iCCP': // Embedded ICC Profile + $thisfile_png_chunk_type_text['header'] = $chunk; + list($profilename, $compressiondata) = explode("\x00", $chunk['data'], 2); + $thisfile_png_chunk_type_text['profile_name'] = $profilename; + $thisfile_png_chunk_type_text['compression_method'] = getid3_lib::BigEndian2Int(substr($compressiondata, 0, 1)); + $thisfile_png_chunk_type_text['compression_profile'] = substr($compressiondata, 1); + + $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['compression_method']); + break; + + + case 'tEXt': // Textual Data + $thisfile_png_chunk_type_text['header'] = $chunk; + list($keyword, $text) = explode("\x00", $chunk['data'], 2); + $thisfile_png_chunk_type_text['keyword'] = $keyword; + $thisfile_png_chunk_type_text['text'] = $text; + + $thisfile_png['comments'][$thisfile_png_chunk_type_text['keyword']][] = $thisfile_png_chunk_type_text['text']; + break; + + + case 'zTXt': // Compressed Textual Data + $thisfile_png_chunk_type_text['header'] = $chunk; + list($keyword, $otherdata) = explode("\x00", $chunk['data'], 2); + $thisfile_png_chunk_type_text['keyword'] = $keyword; + $thisfile_png_chunk_type_text['compression_method'] = getid3_lib::BigEndian2Int(substr($otherdata, 0, 1)); + $thisfile_png_chunk_type_text['compressed_text'] = substr($otherdata, 1); + $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['compression_method']); + switch ($thisfile_png_chunk_type_text['compression_method']) { + case 0: + $thisfile_png_chunk_type_text['text'] = gzuncompress($thisfile_png_chunk_type_text['compressed_text']); + break; + + default: + // unknown compression method + break; + } + + if (isset($thisfile_png_chunk_type_text['text'])) { + $thisfile_png['comments'][$thisfile_png_chunk_type_text['keyword']][] = $thisfile_png_chunk_type_text['text']; + } + break; + + + case 'iTXt': // International Textual Data + $thisfile_png_chunk_type_text['header'] = $chunk; + list($keyword, $otherdata) = explode("\x00", $chunk['data'], 2); + $thisfile_png_chunk_type_text['keyword'] = $keyword; + $thisfile_png_chunk_type_text['compression'] = (bool) getid3_lib::BigEndian2Int(substr($otherdata, 0, 1)); + $thisfile_png_chunk_type_text['compression_method'] = getid3_lib::BigEndian2Int(substr($otherdata, 1, 1)); + $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['compression_method']); + list($languagetag, $translatedkeyword, $text) = explode("\x00", substr($otherdata, 2), 3); + $thisfile_png_chunk_type_text['language_tag'] = $languagetag; + $thisfile_png_chunk_type_text['translated_keyword'] = $translatedkeyword; + + if ($thisfile_png_chunk_type_text['compression']) { + + switch ($thisfile_png_chunk_type_text['compression_method']) { + case 0: + $thisfile_png_chunk_type_text['text'] = gzuncompress($text); + break; + + default: + // unknown compression method + break; + } + + } else { + + $thisfile_png_chunk_type_text['text'] = $text; + + } + + if (isset($thisfile_png_chunk_type_text['text'])) { + $thisfile_png['comments'][$thisfile_png_chunk_type_text['keyword']][] = $thisfile_png_chunk_type_text['text']; + } + break; + + + case 'bKGD': // Background Color + $thisfile_png_chunk_type_text['header'] = $chunk; + switch ($thisfile_png['IHDR']['raw']['color_type']) { + case 0: + case 4: + $thisfile_png_chunk_type_text['background_gray'] = getid3_lib::BigEndian2Int($chunk['data']); + break; + + case 2: + case 6: + $thisfile_png_chunk_type_text['background_red'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth'])); + $thisfile_png_chunk_type_text['background_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth'])); + $thisfile_png_chunk_type_text['background_blue'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 2 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth'])); + break; + + case 3: + $thisfile_png_chunk_type_text['background_index'] = getid3_lib::BigEndian2Int($chunk['data']); + break; + + default: + break; + } + break; + + + case 'pHYs': // Physical Pixel Dimensions + $thisfile_png_chunk_type_text['header'] = $chunk; + $thisfile_png_chunk_type_text['pixels_per_unit_x'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 4)); + $thisfile_png_chunk_type_text['pixels_per_unit_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 4)); + $thisfile_png_chunk_type_text['unit_specifier'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 8, 1)); + $thisfile_png_chunk_type_text['unit'] = $this->PNGpHYsUnitLookup($thisfile_png_chunk_type_text['unit_specifier']); + break; + + + case 'sBIT': // Significant Bits + $thisfile_png_chunk_type_text['header'] = $chunk; + switch ($thisfile_png['IHDR']['raw']['color_type']) { + case 0: + $thisfile_png_chunk_type_text['significant_bits_gray'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1)); + break; + + case 2: + case 3: + $thisfile_png_chunk_type_text['significant_bits_red'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1)); + $thisfile_png_chunk_type_text['significant_bits_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1)); + $thisfile_png_chunk_type_text['significant_bits_blue'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 1)); + break; + + case 4: + $thisfile_png_chunk_type_text['significant_bits_gray'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1)); + $thisfile_png_chunk_type_text['significant_bits_alpha'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1)); + break; + + case 6: + $thisfile_png_chunk_type_text['significant_bits_red'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1)); + $thisfile_png_chunk_type_text['significant_bits_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1)); + $thisfile_png_chunk_type_text['significant_bits_blue'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 1)); + $thisfile_png_chunk_type_text['significant_bits_alpha'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 3, 1)); + break; + + default: + break; + } + break; + + + case 'sPLT': // Suggested Palette + $thisfile_png_chunk_type_text['header'] = $chunk; + list($palettename, $otherdata) = explode("\x00", $chunk['data'], 2); + $thisfile_png_chunk_type_text['palette_name'] = $palettename; + $sPLToffset = 0; + $thisfile_png_chunk_type_text['sample_depth_bits'] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, 1)); + $sPLToffset += 1; + $thisfile_png_chunk_type_text['sample_depth_bytes'] = $thisfile_png_chunk_type_text['sample_depth_bits'] / 8; + $paletteCounter = 0; + while ($sPLToffset < strlen($otherdata)) { + $thisfile_png_chunk_type_text['red'][$paletteCounter] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes'])); + $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes']; + $thisfile_png_chunk_type_text['green'][$paletteCounter] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes'])); + $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes']; + $thisfile_png_chunk_type_text['blue'][$paletteCounter] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes'])); + $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes']; + $thisfile_png_chunk_type_text['alpha'][$paletteCounter] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes'])); + $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes']; + $thisfile_png_chunk_type_text['frequency'][$paletteCounter] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, 2)); + $sPLToffset += 2; + $paletteCounter++; + } + break; + + + case 'hIST': // Palette Histogram + $thisfile_png_chunk_type_text['header'] = $chunk; + $hISTcounter = 0; + while ($hISTcounter < strlen($chunk['data'])) { + $thisfile_png_chunk_type_text[$hISTcounter] = getid3_lib::BigEndian2Int(substr($chunk['data'], $hISTcounter / 2, 2)); + $hISTcounter += 2; + } + break; + + + case 'tIME': // Image Last-Modification Time + $thisfile_png_chunk_type_text['header'] = $chunk; + $thisfile_png_chunk_type_text['year'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 2)); + $thisfile_png_chunk_type_text['month'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 1)); + $thisfile_png_chunk_type_text['day'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 3, 1)); + $thisfile_png_chunk_type_text['hour'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 1)); + $thisfile_png_chunk_type_text['minute'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 5, 1)); + $thisfile_png_chunk_type_text['second'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 6, 1)); + $thisfile_png_chunk_type_text['unix'] = gmmktime($thisfile_png_chunk_type_text['hour'], $thisfile_png_chunk_type_text['minute'], $thisfile_png_chunk_type_text['second'], $thisfile_png_chunk_type_text['month'], $thisfile_png_chunk_type_text['day'], $thisfile_png_chunk_type_text['year']); + break; + + + case 'oFFs': // Image Offset + $thisfile_png_chunk_type_text['header'] = $chunk; + $thisfile_png_chunk_type_text['position_x'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 4), false, true); + $thisfile_png_chunk_type_text['position_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 4), false, true); + $thisfile_png_chunk_type_text['unit_specifier'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 8, 1)); + $thisfile_png_chunk_type_text['unit'] = $this->PNGoFFsUnitLookup($thisfile_png_chunk_type_text['unit_specifier']); + break; + + + case 'pCAL': // Calibration Of Pixel Values + $thisfile_png_chunk_type_text['header'] = $chunk; + list($calibrationname, $otherdata) = explode("\x00", $chunk['data'], 2); + $thisfile_png_chunk_type_text['calibration_name'] = $calibrationname; + $pCALoffset = 0; + $thisfile_png_chunk_type_text['original_zero'] = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 4), false, true); + $pCALoffset += 4; + $thisfile_png_chunk_type_text['original_max'] = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 4), false, true); + $pCALoffset += 4; + $thisfile_png_chunk_type_text['equation_type'] = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 1)); + $pCALoffset += 1; + $thisfile_png_chunk_type_text['equation_type_text'] = $this->PNGpCALequationTypeLookup($thisfile_png_chunk_type_text['equation_type']); + $thisfile_png_chunk_type_text['parameter_count'] = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 1)); + $pCALoffset += 1; + $thisfile_png_chunk_type_text['parameters'] = explode("\x00", substr($chunk['data'], $pCALoffset)); + break; + + + case 'sCAL': // Physical Scale Of Image Subject + $thisfile_png_chunk_type_text['header'] = $chunk; + $thisfile_png_chunk_type_text['unit_specifier'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1)); + $thisfile_png_chunk_type_text['unit'] = $this->PNGsCALUnitLookup($thisfile_png_chunk_type_text['unit_specifier']); + list($pixelwidth, $pixelheight) = explode("\x00", substr($chunk['data'], 1)); + $thisfile_png_chunk_type_text['pixel_width'] = $pixelwidth; + $thisfile_png_chunk_type_text['pixel_height'] = $pixelheight; + break; + + + case 'gIFg': // GIF Graphic Control Extension + $gIFgCounter = 0; + if (isset($thisfile_png_chunk_type_text) && is_array($thisfile_png_chunk_type_text)) { + $gIFgCounter = count($thisfile_png_chunk_type_text); + } + $thisfile_png_chunk_type_text[$gIFgCounter]['header'] = $chunk; + $thisfile_png_chunk_type_text[$gIFgCounter]['disposal_method'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1)); + $thisfile_png_chunk_type_text[$gIFgCounter]['user_input_flag'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1)); + $thisfile_png_chunk_type_text[$gIFgCounter]['delay_time'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 2)); + break; + + + case 'gIFx': // GIF Application Extension + $gIFxCounter = 0; + if (isset($thisfile_png_chunk_type_text) && is_array($thisfile_png_chunk_type_text)) { + $gIFxCounter = count($thisfile_png_chunk_type_text); + } + $thisfile_png_chunk_type_text[$gIFxCounter]['header'] = $chunk; + $thisfile_png_chunk_type_text[$gIFxCounter]['application_identifier'] = substr($chunk['data'], 0, 8); + $thisfile_png_chunk_type_text[$gIFxCounter]['authentication_code'] = substr($chunk['data'], 8, 3); + $thisfile_png_chunk_type_text[$gIFxCounter]['application_data'] = substr($chunk['data'], 11); + break; + + + case 'IDAT': // Image Data + $idatinformationfieldindex = 0; + if (isset($thisfile_png['IDAT']) && is_array($thisfile_png['IDAT'])) { + $idatinformationfieldindex = count($thisfile_png['IDAT']); + } + unset($chunk['data']); + $thisfile_png_chunk_type_text[$idatinformationfieldindex]['header'] = $chunk; + break; + + + case 'IEND': // Image Trailer + $thisfile_png_chunk_type_text['header'] = $chunk; + break; + + + default: + //unset($chunk['data']); + $thisfile_png_chunk_type_text['header'] = $chunk; + $ThisFileInfo['warning'][] = 'Unhandled chunk type: '.$chunk['type_text']; + break; + } + } + + return true; + } + + function PNGsRGBintentLookup($sRGB) { + static $PNGsRGBintentLookup = array( + 0 => 'Perceptual', + 1 => 'Relative colorimetric', + 2 => 'Saturation', + 3 => 'Absolute colorimetric' + ); + return (isset($PNGsRGBintentLookup[$sRGB]) ? $PNGsRGBintentLookup[$sRGB] : 'invalid'); + } + + function PNGcompressionMethodLookup($compressionmethod) { + static $PNGcompressionMethodLookup = array( + 0 => 'deflate/inflate' + ); + return (isset($PNGcompressionMethodLookup[$compressionmethod]) ? $PNGcompressionMethodLookup[$compressionmethod] : 'invalid'); + } + + function PNGpHYsUnitLookup($unitid) { + static $PNGpHYsUnitLookup = array( + 0 => 'unknown', + 1 => 'meter' + ); + return (isset($PNGpHYsUnitLookup[$unitid]) ? $PNGpHYsUnitLookup[$unitid] : 'invalid'); + } + + function PNGoFFsUnitLookup($unitid) { + static $PNGoFFsUnitLookup = array( + 0 => 'pixel', + 1 => 'micrometer' + ); + return (isset($PNGoFFsUnitLookup[$unitid]) ? $PNGoFFsUnitLookup[$unitid] : 'invalid'); + } + + function PNGpCALequationTypeLookup($equationtype) { + static $PNGpCALequationTypeLookup = array( + 0 => 'Linear mapping', + 1 => 'Base-e exponential mapping', + 2 => 'Arbitrary-base exponential mapping', + 3 => 'Hyperbolic mapping' + ); + return (isset($PNGpCALequationTypeLookup[$equationtype]) ? $PNGpCALequationTypeLookup[$equationtype] : 'invalid'); + } + + function PNGsCALUnitLookup($unitid) { + static $PNGsCALUnitLookup = array( + 0 => 'meter', + 1 => 'radian' + ); + return (isset($PNGsCALUnitLookup[$unitid]) ? $PNGsCALUnitLookup[$unitid] : 'invalid'); + } + + function IHDRcalculateBitsPerSample($color_type, $bit_depth) { + switch ($color_type) { + case 0: // Each pixel is a grayscale sample. + return $bit_depth; + break; + + case 2: // Each pixel is an R,G,B triple + return 3 * $bit_depth; + break; + + case 3: // Each pixel is a palette index; a PLTE chunk must appear. + return $bit_depth; + break; + + case 4: // Each pixel is a grayscale sample, followed by an alpha sample. + return 2 * $bit_depth; + break; + + case 6: // Each pixel is an R,G,B triple, followed by an alpha sample. + return 4 * $bit_depth; + break; + } + return false; + } + +} + + +?>
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